1. Field of the Invention
This invention relates to computer architecture. In particular, the invention relates to processor-based pattern recognition.
2. Description of Related Art
Recognizing an unknown pattern such as speech or handwriting can be accomplished by determining how closely the features of the unknown pattern match to the features of a known, ideal pattern. The features of both the known and unknown patterns can be represented by a multi-dimensional vector in a feature space, with one feature for each dimension.
The comparison, or matching, of the feature vectors between the unknown pattern and the known pattern(s) is inherently a time-consuming process. When the dimensionality of the feature space becomes large, the computations become prohibitively high. In many applications where real-time processing is desired, it is preferable to perform these computations as fast as possible.
In addition, the comparison or matching process typically follow rigid and fixed calculations. Contextual information in forms of weighting factors or probability density function are not fully exploited. The result is that the classification is not robust and flexible, resulting in high classification errors.
Therefore there is a need in the technology to provide a robust and flexible method to perform pattern recognition at a high processing rate.
The present invention is a method and apparatus to determine a similarity measure between first and second patterns. First and second storages store first and second feature vectors which represent the first and second patterns, respectively. A similarity estimator is coupled to the first and second storages to compute a similarity probability of the first and second feature vectors using a piecewise linear probability density function (PDF). The similarity probability corresponds to the similarity measure.